Molten metal supplying apparatus

ABSTRACT

A molten metal supplying apparatus has an electromagnetic pump for supplying molten metal under electromagnetic forces through a molten metal feed tube to a die-casting machine. An adapter is provided for maintaining molten metal therein at the same surface level as that of molten metal which is kept in a molten metal holding furnace at a prescribed temperature. The molten metal holding furnace is movable toward and away from a molten metal receiving member of the die-casing machine. An oxidized layer is prevented from being formed in the molten metal as it is fed through the feed tube, and the feed tube can easily be inspected and serviced. An orifice member is disposed in the feed tube for supplying even a small amount of molten metal accurately to the molten metal receiving member.

TECHNICAL FIELD

The present invention relates to a molten metal supplying apparatus forsupplying a mold, using an electromagnetic pump, with molten metal thatis maintained at a prescribed temperature in a molten metal holdingfurnace, in a vertical die casting machine, a horizontal die castingmachine, a low-pressure die casting machine, or a gravity die castingmachine, and more particularly to a molten metal supplying apparatuswhich is capable of preventing the temperature of molten metal frombeing lowered and also effectively preventing an oxidized layer frombeing produced on molten metal when the molten metal is supplied from amolten metal holding furnace into a mold or die, and which is alsocapable of supplying even a small amount of molten metal accurately intothe mold.

BACKGROUND OF THE INVENTION

As disclosed in Japanese Laid-Open Patent Publication No. 61-180666,there has been employed in the art a molten metal supplying apparatusfor supplying molten metal from a molten metal holding furnace into amold or molten metal receiving member through a distribution tube systemwhich has an electromagnetic pump. In one arrangement, theelectromagnetic pump is disposed below the surface level of molten metalin the holding furnace According to another system, the electromagneticpump is positioned above the surface level of molten metal in theholding furnace, and air pressure and the electromagnetic pump arerelied upon to supply the molten metal from the holding furnace into themold.

In the former structure, the distribution tube connecting the holdingfurnace and the molten metal receiving member is required to be adjustedto the construction of the molten metal receiving member, i.e., to theposition of the mold or the like, and hence the distribution tube iscomplex in structure and many joints are employed. Accordingly, thedanger of leakage of the molten metal somewhere in the distribution tubeexists. Since the distribution tube is located below the surface levelof the molten metal in the holding furnace, if the distribution tube hasto be inspected or serviced, all of the molten metal must be removedfrom the holding furnace. Such a process is time-consuming, and hence isnot preferable from the standpoint of the production efficiency.

The latter construction is not versatile as it can only be used withlow-pressure die-casting machines. Inasmuch a the molten metal receivingmember is positioned higher than the surface level of the molten metalin the holding furnace, when the molten metal is supplied from theholding furnace to the molten metal receiving member, part of the moltenmetal is brought into contact with air and hence oxidized. After themolten metal has been supplied to the mold, an excessive amount ofsupplied molten metal cannot fully be returned into the holding furnace,and is partly deposited on the inner peripheral surface of thedistribution tube. The deposited molten metal is oxidized by contactwith air, and the oxidized deposit narrows the molten metal flow passagein the distribution tube. As a result, the rate of flow of the moltenmetal through the distribution tube in a next casting process is varied.With the conventional molten metal supplying apparatus of the typedescribed above, the molten metal holding furnace and the molten metalreceiving member are fixed in position. When the molten metal issupplied, therefore, the distribution tube is expanded and contractedbecause of an increase in the temperature of the distribution tube. As aconsequence, the durability of packings or sealing members attached tothe joints of the distribution tube is reduced.

DISCLOSURE OF THE INVENTION

In view of the aforesaid shortcomings of the conventional molten metalsupplying apparatus, it is an object of the present invention to providea molten metal supplying apparatus which can prevent molten metalsupplied from a molten metal holding furnace to a mold from producingoxidized layers, can prevent the temperature of the molten metal frombeing lowered, can stabilize the rate of flow of the molten metalsupplied over a long period of time, and can supply even a small amountof molten metal accurately to the mold.

To achieve the above object, there is provided in accordance with thepresent invention a molten metal supplying apparatus comprising: aconstant-level molten metal holding furnace; a linear molten metal feedtube for feeding molten metal from the constant-level molten metalholding furnace to a molten metal receiving member; an electromagneticpump disposed in the molten metal feed tube; and an adapter disposedbetween a tip end of the molten metal feed tube and the molten metalreceiving member including an injection sleeve and having a molten metalfeed passage capable of keeping a surface level of molten metal thereinat a position higher than the molten metal feed tube, the arrangementbeing such that while the molten metal feed tube is being filled withmolten metal, the electromagnetic pump is actuated to discharge themolten metal from the molten metal feed tube to the molten metalreceiving member.

The molten metal feed tube has a heater mounted on the outer surface ofat least the tip end thereof.

According to the present invention, there is also provided a moltenmetal supplying apparatus comprising: a constant-level molten metalholding furnace; a linear molten metal feed tube for feeding moltenmetal from the constant-level molten metal holding furnace to a moltenmetal receiving member; and an electromagnetic pump disposed in themolten metal feed tube, at least the constant-level molten metal holdingfurnace being movable toward and away from the molten metal receivingmember.

The molten metal supplying apparatus further comprises a linear actuatorcoupled to the constant-level molten metal holding furnace for movingthe constant-level molten metal holding furnace toward and away from themolten metal receiving member.

The molten metal supplying apparatus further comprises a resilientmember mounted on the constant-level molten metal holding furnace forresiliently moving the constant-level molten metal holding furnacetoward and away from the molten metal receiving member.

The molten metal supplying apparatus further comprises wheels mounted ona lower end of the constant-level molten metal holding furnace forallowing the constant-level molten metal holding furnace to move towardand away from aid molten metal receiving member.

The molten metal supplying apparatus further comprises a mount on whichthe constant-level molten metal holding furnace is mounted, and a soleplate on which the mount is movable toward and away from the moltenmetal receiving member with a low coefficient of friction.

The molten metal supplying apparatus further comprises a plurality ofleaf springs mounted on the sole plate and supporting the mount.

According to the present invention, there is further provided a moltenmetal supplying apparatus comprising: a molten metal holding furnace;and a molten metal feed tube for supplying molten metal from the moltenmetal holding furnace to a molten metal receiving member with anelectromagnetic pump, the molten metal feed tube having a restriction inat least one location, the restriction having a cross-sectional areasmaller than the cross-sectional area of a flow passage of the moltenmetal feed tube.

The restriction comprises an orifice member disposed in the molten metalfeed tube.

The orifice member comprises a disc having at least one recess forreducing the cross-sectional area of the flow passage of the moltenmetal feed tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view of a diecasting machine inwhich a molten metal supplying apparatus of the present invention isincorporated;

FIG. 2 is a horizontal cross-sectional view of an adapter and aninjection sleeve of the molten metal supplying apparatus;

FIG. 3 is an elevational view of a die-casting machine incorporating amolten metal supplying apparatus according to another embodiment of thepresent invention

FIGS. 4 through 6 are vertical cross-sectional views of adaptersaccording to other embodiments of the present invention;

FIG. 7 is a perspective view of an orifice in the tip end of a feed tubeof the apparatus according to to the present invention; and

FIGS. 8 through 13 are front elevational views of orifices to beincorporated in the tip end of the feed tube according to the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of molten metal supplying apparatus according tothe present invention will be described below in detail with referenceto the accompanying drawings.

The reference numeral 10 in FIG. 1 represents a molten metal holdingfurnace for holding molten metal at a constant surface level. The moltenmetal holding furnace 10 is supported on a base 14 disposed horizontallyon a floor 12. The base 14 supports thereon an air cylinder as a linearactuator, and has a pair of parallel rails 18a, 18b on its uppersurface. Wheels 20a, 20b are rollingly mounted on the rails 18a, 18b,and support a casing 22 of the molten metal holding furnace 10. Thecasing 22 has an arm 24 projecting from the lower surface thereof andcoupled to a piston rod 26 extending from the air cylinder 16.

The casing 22 has a wall containing a heat insulating member 28 whichsurrounds an inner space 30 that accommodates a constant-level moltenmetal holding furnace 32 substantially centrally therein. Theconstant-level molten metal holding furnace 32 has openings 34 in itslower end, and a plurality of heaters 36 in its upper portion. Ahorizontally extending molten metal discharge tube 40 is supported onthe casing 22 near its upper end and extending into the inner space 30.As can easily be seen from FIG. 1, the molten metal discharge tube 40 ispositioned slightly lower than the surface level 42 of molten metalmaintained by the constant-level molten metal holding furnace 32. Themolten metal discharge tube 40 has a tip end coupled to an intermediatefeed tube 44.

A bracket 46 is horizontally mounted on a side wall surface of thecasing 22, and arm stand 48 is vertically mounted on the distal end ofthe bracket 46. An iron core holder 50 is mounted on the arm stand 48.The intermediate feed tube 44 is held by the molten metal discharge tube40 and the iron core holder 50.

An electromagnetic pump 60 is retained in position on the bracket 46.The electromagnetic pump 60 includes a coil 62 surrounding theintermediate tube 44 and an iron core 64 extending longitudinally in theintermediate distribution tube 44. The iron core 64 is surrounded by aniron core guard 66 which is heated to a prescribed temperature by aniron core guard heater. The iron core holder 50 has a passage 74connecting a lower end of the intermediate feed tube 44 and an end feedtube 72, such that the molten metal discharge tube 40, the intermediatefeed tube 44, and the end feed tube 72 are held coaxially with eachother. A coil heater 76 is disposed around the tip feed tube 72 andsurrounded by a cylindrical casing 78.

An adapter 80 is mounted on the distal end of the end feed tube 72. Asshown in FIG. 1, the adapter 80 has an upstanding passage 84 formaintaining a surface level 82 of molten metal at the same height asthat of the surface level 42 by the constant-level molten metal holdingfurnace 32. The passage 84 of the adapter 80 opens into a recess 92defined in an injection sleeve 90 which opens into a mold or die (notshown). The recess 92 is of a hemispherical shape complementary to thehemispherical tip end of the adapter 80, with a seal member 94interposed between the recess 92 and the tip end of the adapter 80. Themolten metal discharge tube 40, the intermediate distribution tube 44,and the end feed tube 72 jointly constitute a molten metal supply tube.Denoted at 96 is a plunger, 98 a plunger tip mounted on the tip end ofthe plunger 96 and disposed in the injection sleeve 90, and 99 a heaterwound around the intermediate feed tube 44.

The molten metal supplying apparatus is basically constructed asdescribed above. Now, its operation and advantages will be describedbelow.

Molten metal M stored in the holding furnace 10 has its surface level 42maintained by the constant-level holding furnace 32 at a positionslightly higher than the molten metal discharge tube 40, theintermediate feed tube 44, and the end feed tube 72. Therefore, themolten metal M reaches the adapter 80 through the molten metal dischargetube 40, the intermediate feed tube 44, and the end feed tube 72. Thesurface level 82 of the molten metal in the adapter 80 is consequentlyat the same height as that of the surface level 42. The heater 36 isenergized to keep the molten metal in the constant-level holding furnace32 at a prescribed temperature.

The electromagnetic pump 60 is actuated under this condition. As is wellknown, the electromagnetic pump 60 operates by inducing an electriccurrent in the molten metal M in the intermediate feed tube 44 andgenerating an electromagnetic force with the induced current and amagnetic field produced by the coil 62 to forcibly move the molten metalM toward the injection sleeve 90. The molten metal M is discharged fromthe adapter 80 into the injection sleeve 90. A cylinder (not shown) isactuated to displace the plunger 96 in the direction of the arrow toenable the plunger tip 9 to push the molten metal forcibly into the moldor die (not shown). After a certain period of time has elapsed, asolidified casting can be produced from the mold.

According to the present invention, the molten metal discharge tube 40,the intermediate feed tube 44, and the end feed tube 72 aresubstantially linearly arranged, i.e., coaxially arranged. Therefore,the feed system for feeding the molten metal from the holding furnace 10to the injection sleeve 90 is highly simplified. Since the joints of thefeed system are few in number, the danger of leakage of the molten metalas it is fed is small. Because it is possible to substantially reducethe entire length of the molten metal discharge tube 40, theintermediate feed tube 44, and the end feed tube 72, any reduction inthe temperature of the molten metal M when it is fed therethrough can beminimized. Such a temperature drop of the molten metal M can further beeffectively prevented by the coil heaters 99, 76 disposed around theintermediate feed tube 44 and the end feed tube 72. With the presentinvention, the adapter 80 is mounted on the distal end of the end feedtube 72 for providing the same surface level of molten metal as that 42of molten metal by the constant-level holding furnace 32. Therefore, itis possible to fill the molten metal discharge tube 40, the intermediatefeed tube 44, and the end feed tube 72 with the molten metal M at alltimes. Accordingly, the molten metal M does not produce any oxidizedlayer as it is held out of contact with oxygen in the atmosphere.Defects in castings, which would otherwise be caused by such oxidizedlayer, are thus prevented. Furthermore, the problem of oxidized depositson the inner peripheral surfaces of the tubes, which would narrow thediameters of the tubes and make the rate of flow of the molten metalthrough the tubes unstable, can also be prevented.

For inspecting and servicing the molten metal discharge tube 40, theintermediate feed tube 44, or the end feed tube 72, it is not necessaryto remove all of the molten metal M from the holding surface since theconstant-level holding furnace 32 is employed. Such an inspecting andservicing process can thus be performed easily. The air cylinder 16 isactuated to urg the casing 22 in the direction of the arrow A at alltimes during operation, for thereby pressing the hemispherical end ofthe adapter 80 into the recess 92 of the injection sleeve 90 undercertain pressure. Even if the feed system is expanded by the heat of themolten metal supplied to the molten metal discharge tube 40, theintermediate feed tube 44, and the end feed tube 72, the adapter 80 isnot loosened from the injection sleeve 90. As a consequence, no moltenmetal will leak from between the injection sleeve 90 and the adapter 80.By inactivating the air cylinder 16 to allow the casing 22 to bedisplaced in the direction of the arrow B, the molten metal dischargetube 40, the intermediate distribution tube 44, or the end feed tube 72may easily be detached for inspection or servicing.

FIG. 3 shows a molten metal supplying apparatus according anotherembodiment of the present invention. Those parts in FIG. 3 which areidentical to those shown in FIG. 1 are denoted by identical referencenumerals, and will not be described in detail. This holds true for otherembodiments or modifications.

In the embodiment of FIG. 3, a molten metal holding furnace 10 is notsupported on any rails on a base, but is supported on a sole plate 120directly mounted on a floor 12, the sole plate 120 being slidable on thefloor 12 with a low coefficient of friction. A mount 124 is supportedabove the sole plate 120 substantially parallel thereto by leaf springs122a, 122b mounted on the sole plate 120, and the holding furnace 10 ismounted on the mount 124. A pusher 126 of a vertically bent shape iscoupled to one end of the sole plate 120. A coil spring 128 is held atone end against the upper distal end of the pusher 126, and has its tipend held against a side wall of a molten metal holding furnace 10 fornormally urging the holding furnace 10 in the direction of the arrow A.

With this arrangement, even if the molten metal discharge tube 40, theintermediate distribution tube 44, or the end distribution tube 72 isheated by the supplied molten metal and substantially increased in itslength, as described above, the tip end of he adapter 80 is held inintimate contact with the injection sleeve 90 so that they will not comeapart.

FIGS. 4 through 9 show other embodiments of molten metal supplyingapparatus according to the present invention. These embodiments areparticularly directed to modified adapters 80.

FIG. 4 shows an arrangement for use with a low-pressure die-castingmachine. The low-pressure die-casting machine has a mold or die 100 withits lower end attached to a bent stalk used as an adapter 80a. An endfeed tube 72 is coupled to the lower end of the adapter 80a. Moltenmetal supplied to the adapter 80a has a surface level higher than thesurface level 42 in the holding furnace.

FIG. 5 illustrates an arrangement for use with a horizontal injectiondie-casting machine. An adapter 80b which is bent as with the firstembodiment is coupled to and opens into an injection sleeve The surfacelevel 82b of molten metal in the adapter 80b is higher than the surfacelevel 42 in the holding furnace.

FIG. 6 shows a block used as an adapter 80c with a vertical die-castingmachine. The surface level 82c of molten metal in the adapter 80c ishigher than the surface level 42 in the holding furnace.

The adapters shown in FIGS. 4 through 6 offer the same advantages asthose of the first embodiment.

FIGS. 7 and 8 show still another embodiment of the present invention. Asubstantially circular orifice member 200 is disposed in the end feedtube 72 and has a restriction of a cross-sectional area smaller than thecross-sectional are of the inner passage of the end feed tube 72. Asshown in FIG. 7 and 8 the orifice member 200 comprises a disc 202 havingthe same outside diameter as the inside diameter of the end feed tube72, the disc 202 having two upper and lower U-shaped or semicircularrecesses 204a, 204b defined in its outer peripheral edge. The tworecesses 204a, 204b prevent air from being stagnant in the end feed tube72. Particularly, when the molten metal discharge tube 40, theintermediate feed tube 44, and the end feed tube 72 are emptied forinspection and servicing, the molten metal M is prevented from beingleft in these tubes. The orifice member 200 may be of any of variousconfigurations.

In FIG. 9, a pair of upper and lower rectangular recesses 206a, 206b isdefined in a disc 202.

In FIG. 10, a pair of V-shaped recesses or notches 208a, 208a is definedin a disc 202.

In FIG. 11, a disc 202 has a pair of segmental recesses 210a, 210b.

In FIG. 12, no recess is defined in the outer peripheral edge of a disc202, but an oblong recess 212 is defined diametrically in the disc 202.

In FIG. 13, semicircular recesses 214a through 214d, similar to thoseshown in FIG. 8, are defined at angular intervals of 90°.

The orifice member 200 disposed in the end feed tube 72 offers thefollowing additional advantages: Heretofore, when molten metal isdischarged from the tip end of the adapter, the time in which the moltenmetal is discharged has been adjusted or the voltage applied to theelectromagnetic pump 60 has been regulated. This conventional method hasbeen unable to stabilize the amount of molten metal supplied. Forexample, it has been impossible to deliver molten metal M less than 500g into the injection sleeve 90. According to the present invention, whensupplying molten metal M into the injection sleeve 90, the orificemember 200 in the end feed tube 72 restricts the molten metal M therebyto stabilize the amount of supplied molten metal. When 500 g of moltenmetal M was fed according to the present invention, the error was about±1.5%. In the illustrated embodiments, the orifice member 200 isdisposed in the end feed tube 72. However, the orifice member 200 may bedisposed in the molten metal discharge tube 40 or the intermediate feedtube 44. Alternatively, the orifice member may be disposed as a spacersandwiched between the molten metal discharge tube 4 and theintermediate feed tube 44, or between the intermediate feed tube 44 andthe end feed tube 72, or two more orifice members may be disposed in thefeed system. The orifice member may have only one recess if there is agap defined as an air bleeder between the outer periphery of the orificemember and the inner peripheral surface of the molten metal dischargetube 40, the intermediate feed tube 44, or the end feed tube 72 forallowing sufficient air to be released. Furthermore, the orifice member200 may not be separate from, but may be made integral with, the moltenmetal discharge tube 40, the intermediate feed tube 44, or the end feedtube 72, or a structure similar to the orifice member 200 may beincorporated in the iron core holder 50.

INDUSTRIAL APPLICABILITY

With the present invention, as described above, a casting process iscarried out while molten metal is being filled in the molten metal feedsystem between the molten metal holding furnace and the injectionsleeve. Therefore, the molten metal is prevented from contacting air,and as a result no oxidized layer is produced in the molten metal or thetemperature of the molten metal is prevented from being lowered. Sinceno oxidized layer is deposited in the molten metal feed system, theinside diameters of the feed tubes are not reduced, and hence the amountof supplied molten metal is stabilized. The danger of defects inproduced castings is therefore minimized. The molten metal feed system,particularly the adapter, is movable toward and away from the injectionsleeve. Under normal condition, the adapter is pressed against theinjection sleeve during a casting process. Even if the molten metal feedsystem is expanded by the heat of the molten metal carried therein, noundue stress is applied to the components including the feed systemsince the adapter is pressed against the injection sleeve underprescribed pressure by the linear actuator which may be an air cylinder,a coil spring, or the like. Consequently, these components will not bebroken or damaged. Inasmuch as the seal member disposed between theadapter and the injection sleeve is not damaged, no molten metal willleak from between the adapter and the injection sleeve. For inspectingor servicing the molten metal discharge tube, the intermediate feedtube, or the end feed tube, the molten metal holding furnace isdisplaced by inactivating the air cylinder or against the resiliency ofthe coil spring in order to remove these tubes easily from the injectionsleeve or the molten metal holding furnace. Moreover, the restriction ofa cross-sectional area smaller than the cross-sectional area of thepassage in the molten metal feed system is provided in at least onelocation in the molten metal feed system. As a result, even when a smallamount of molten metal is supplied, the amount of supplied molten metalis stabilized, and can be controlled highly accurately.

Although certain preferred embodiments have been shown and described, itshould be understood that many changes and modifications may be madetherein without departing from the scope of the appended claims.

We claim:
 1. A molten metal supplying apparatus comprising: aconstant-level molten metal holding furnace; a substantially linearmolten metal feed tube for feeding molten metal from the constant-levelmolten metal holding furnace to a molten metal receiving member; anelectromagnetic pump disposed in said molten metal feed tube; and anadapter disposed between a tip end of said molten metal feed tube andthe molten metal receiving member including an injection sleeve and saidadapter having a molten metal feed passage capable of keeping a surfacelevel of molten metal therein at a position higher than said moltenmetal feed tube, wherein a longitudinal axis of said molten metal feedtube is disposed horizontally along a straight line and below a surfacelevel of said molten metal maintained in said constant-level moltenmetal holding furnace; the arrangement being such that while said moltenmetal feed tube is being filled with molten metal, said electromagneticpump is actuated to discharge the molten metal from the molten metalfeed tube to said molten metal receiving member.
 2. A molten metalsupplying apparatus according to claim 1, wherein said molten metal feedtube has a heater mounted on the outer surface of at least the tip endthereof.
 3. A molten metal supplying apparatus comprising: aconstant-level molten metal holding furnace; a linear molten metal feedtube for feeding molten metal from the constant-level molten metalholding furnace to a molten metal receiving member; and anelectromagnetic pump disposed in said molten metal feed tube, wherein alongitudinal axis of said molten metal feed tube is disposedhorizontally along a straight line, and at least said constant-levelmolten metal holding furnace being movable toward and away from saidmolten metal receiving member.
 4. A molten metal supplying apparatusaccording to claim 3, further comprising a linear actuator coupled tothe constant-level molten metal holding furnace for moving theconstant-level molten metal holding furnace toward and away from themolten metal receiving member.
 5. A molten metal supplying apparatusaccording to claim 3, further comprising a resilient member mounted onthe constant-level molten metal holding furnace for resiliently movingthe constant-level molten metal holding furnace toward and away from themolten metal receiving member.
 6. A molten metal supplying apparatusaccording to claim 5, further including a mount on which theconstant-level molten metal holding furnace is mounted, and a sole plateon which the mount is movable toward and away from the molten metalreceiving member with a low coefficient of friction.
 7. A molten metalsupplying apparatus according to claim 6, further including a pluralityof leaf springs mounted on the sole plate and supporting the mount.
 8. Amolten metal supplying apparatus according to claim 3, further includingwheels mounted on a lower end of the constant-level molten metal holdingfurnace for allowing the constant-level molten metal holding furnace tomove toward and away from the molten metal receiving member.
 9. A moltenmetal supplying apparatus according to claim 3, wherein saidlongitudinal axis of said molten metal feed tube is disposed below asurface level of said molten metal maintained in said constant-levelmolten metal holding furnace.
 10. A molten metal supplying apparatusaccording to claim 3, wherein said molten metal feed tube has an orificemember disposed in at least one location inside said feed tube, saidorifice member comprising a disk having a cross-sectional area smallerthan the cross-sectional area of the flow passage of said molten metalfeed tube, and said disk having at least one recess therein for reducingthe cross-sectional area of the flow passage of said molten metal feedtube.
 11. A method for supplying molten metal from an apparatus having aconstant-level molten metal holding furnace; a substantially linearmolten metal feed tube for feeding molten metal from the constant-levelmolten metal holding furnace to a molten metal receiving member, anelectromagnetic pump disposed in said molten metal feed tube, and anadapter disposed between a tip end of said molten metal feed tube andthe molten metal receiving member including an injection sleeve and saidadapter having a molten metal feed passage capable of keeping a surfacelevel of molten metal therein at a position higher than said moltenmetal feed tube, the method steps comprising:filling said molten metalfeed tube with molten metal; and actuating said electromagnetic pump,while filling said molten metal feed tube, to discharge the molten metalfrom the molten metal feed tube to said molten metal receiving member.12. The method as recited in claim 11 wherein said molten metal feedtube includes a heater mounted on the outer surface of at least the tipend thereof and the method further comprises the step of heating saidmolten metal in said molten metal feed tube.